Automatic refrigerant filling

ABSTRACT

A valve controller (1) for filling a refrigerating circuit with refrigerant includes a valve (2), a temperature sensor (3), a pressure sensor (4) and a controller (5). The controller (5) is configured to calculate a parameter from the measurement data of the temperature sensor (3) and/or the pressure sensor (4), and the controller (5) is further configured to activate the valve (2) until the calculated parameter has reached a target value.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent application No. 1 0 2022 109 279.8, filed Apr. 14, 2022, which is incorporated herein by reference as if fully set forth.

TECHNICAL FIELD

The invention relates to a valve controller for filling a refrigerating circuit with refrigerant, comprising a valve, a temperature sensor, a pressure sensor and a controller .

BACKGROUND

Such refrigerating circuits are formed in refrigerating installations. These then operate within optimum parameters, i.e. the desired refrigerating capacity is delivered with minimal energy consumption if these installations are filled with the correct amount of refrigerant. The filling of the refrigerating installation is necessary when a new refrigerating installation is to be commissioned. It is also necessary to check refrigerating installations regularly and to top them up if need be, because they are not absolutely seal-tight or leaks can occur.

SUMMARY

The object of the invention is to make it easier for a refrigerating circuit to be filled with refrigerant.

To achieve the stated object, one or more of the features according to the invention are provided. In particular, to achieve the stated object in the case of valve controllers of the type described at the beginning, according to the invention it is proposed that the controller calculates a parameter from the measurement data of the temperature sensor and/or the pressure sensor, and that the controller activates the valve until the calculated parameter has reached a target value.

Consequently, the current state of the refrigerating circuit can be described by means of a parameter which is calculated from the data of the temperature sensor and/or the pressure sensor. The calculated parameter may for example describe overheating or supercooling.

A target state to be achieved may also be defined. This may be target overheating and/or target supercooling. The target values may for example be dependent on the temperature and pressure conditions at the filling location and vary over the course of the filling. The valve controller is capable of setting the valve by means of the controller in such a way that the desired target value is reached. It is possible that the valve is opened to varying degrees of length or width in dependence on the difference between the calculated parameter and the target value. The valve may be for example a solenoid valve or a motor-driven valve.

Consequently, it may be possible to specify for example a particular volumetric flow rate, which may be dependent on how far the calculated parameter still is from its target value. Because the parameter is calculated from the data of the temperature sensor and/or the pressure sensor, there is no longer any need for a sensor for determining the volumetric flow rate. The valve may also be controlled in dependence on the magnitude of the relative change in the parameter over time.

The risk of improper filling can be reduced or avoided. In particular, it is possible to avoid the installation being filled with too much refrigerant, which then has to be removed again from the installation. This process is very laborious and requires further equipment.

In the case of an advantageous configuration, it may be provided that a memory keeps thermodynamic data on a refrigerant, which data can be included in the calculation performed by the controller.

The calculation of the parameter from the temperature-sensor and/or pressure-sensor data may be dependent on the refrigerant used and its thermodynamic properties.

In addition, it may be provided that a choice can be made between different refrigerants.

Consequently, depending on the refrigerant used, the respective thermodynamic data can be accessed. A valve controller can consequently be used for filling operations with different refrigerants.

In the case of an advantageous configuration, it may be provided that the temperature sensor and/or the pressure sensor is/are wirelessly connected to the controller.

Consequently, the controller can be formed separately from the other components of the valve controller. For example, the components of the valve controller may be attached to the refrigerating circuit at different positions of the refrigerating installation to be filled. For example, temperature sensors are generally externally attached to refrigerant lines. In the case of inaccessible refrigerating circuits, it is not necessary for the user, generally a service engineer or refrigerating engineer, to spend a long time in areas that are difficult to access. The wireless connection may be a Bluetooth connection. Low-cost data transmission is thus possible.

It may additionally be provided that the data transmission takes place on a number of radio channels simultaneously.

Consequently, the data transmission can take place at a higher speed than in the case of transmission on only one radio channel. The data transmission is also better protected against data losses and/or external influences, for example from further radio networks. It is also possible to transmit sensor data from the sensors to the controller and at the same time control commands from the controller to the valve.

Alternatively or in addition, it may be provided that the data transmission takes place at time intervals of less than 10 seconds.

Consequently, real-time monitoring of the filling of the refrigerating circuit is possible, and it is possible to respond quickly to changes in the parameters, or changes in rates of change of the parameters. Relative or absolute rates of change may be considered for example.

In the case of an advantageous configuration, it may be provided that a flow sensor and/or a balance is/are formed and set up to determine the amount of refrigerant delivered into the refrigerating circuit.

The amount of refrigerant delivered can consequently be monitored directly and independently of the data of the temperature sensor or the pressure sensor. This amount may also be determined exclusively by means of the flow sensor or exclusively by means of the balance. These respective sensor data may also be used together for determining the amount of refrigerant delivered. Thus, discrepancies between the filling amounts calculated by means of different methods can be discovered and for example leakages can be detected. The volumetric flow rate of the refrigerant may also be established by the valve itself, for example a through-flow cross section, so that the amount flowing through is obtained by an integration of the volumetric flow rate over time. The time may be an opening time of the valve. This may involve taking the pressure of the refrigerant in the cylinder into account.

In addition, it may be provided that the measurement data of the flow sensor and/or the balance are processed by the controller.

The measurement data of the flow sensor and/or the balance can consequently be used by the controller to monitor the filling operation.

In particular, the expected filling time can be calculated. Depending on the current data situation, the remaining filling time can also be determined. The user can be notified correspondingly. The notification may take place for example by means of an optical and/or acoustic output unit. The user may also be notified when a cylinder, in particular a refrigerant cylinder, has been almost or completely emptied over the course of the filling, or at what time approximately this will be. The user can then change the cylinder at the correct time in order to continue the filling operation. Errors arising in a manual filling operation, which may cause the installation to be damaged, can be avoided.

The filling can consequently take place on the basis of target values of the weight or on the basis of target values of the calculation from the data of the temperature sensor and/or the pressure sensor. The two types of data can also be processed combined.

In the case of an advantageous configuration, it may be provided that a weighing platform is formed on the balance as a standing surface for a cylinder.

Consequently, a cylinder which provides the refrigerant can be placed on the balance in order to monitor the progress of the filling operation by way of the weight loss of the cylinder and to determine from it the amount of refrigerant already introduced during filling. The weighing platform may be configured in such a way as to make it possible for the cylinder to stand safely.

In the case of an advantageous configuration, it may be possible that a largest dimension of the weighing platform corresponds to a largest dimension of the standing area of a cylinder.

In this way, the balance may be adapted to a particular cylinder size. The balance may for example be adapted to a largest cylinder size, so that the balance can also be used for smaller cylinders. The balances may in each case be formed as compactly as possible and at the same time as large as necessary in order to ensure safe standing of the cylinder.

In addition, it may be provided that a diagonal of the weighing platform corresponds to a diameter of the cylinder.

Consequently, the size of the weighing platform may even be smaller than the size of the cylinder. In the state in which it is being used with a cylinder, the weighing platform may be completely covered by the cylinder or the bottom of the cylinder.

In the case of an advantageous configuration, it may be provided that an input unit is formed, enabling the user to establish target parameters, filling amounts and/or other data describing the refrigerating circuit, the refrigerant and/or the filling operation.

The user is consequently capable of specifying all of the necessary data before the beginning of the filling operation, so that the further filling operation can proceed in an automated manner. It is also possible during the filling operation to intervene in the filling operation, for example to update data.

In the case of an advantageous configuration, it may be provided that the controller is set up to control the filling operation in dependence on the amount of refrigerant delivered.

The amount of refrigerant delivered may be determined here for example by means of a flow sensor or a balance, in particular as described above. For example, the magnitude of the volumetric flow rate may be modulated over the time period of the filling operation.

Alternatively or in addition, it may be provided that the controller is set up to perform the filling operation iteratively.

It may thus be envisaged to feed varying amounts of refrigerant to the refrigerating circuit at varying time intervals, depending on the relative and/or absolute deviation of the calculated parameter from the target value. It is also possible to add a defined amount of refrigerant at the beginning of the filling operation and then to perform the further filling iteratively, for example in dependence on the sensor data.

In the case of an advantageous configuration, it may be provided that the controller is set up to detect an inadmissible state.

It may be provided here that an inadmissible state is filling with an excessive amount of refrigerant.

An inadmissible state may also be the occurrence of leakages.

Such states can consequently be detected in an automated manner. These states should be avoided during the filling operation since they can cause damage to the refrigerating installations or refrigerating circuits.

In the case of an advantageous configuration, it may be provided that the controller is set up to inform the user when an inadmissible state is detected.

Consequently, the user can intervene in the operation and for example interrupt it in order to be able to end or rectify the inadmissible state.

In addition, it may be provided that the controller is set up to interrupt the filling operation when an inadmissible state is detected.

The filling operation can consequently be interrupted in an automated manner when an inadmissible state occurs. Damage to the refrigerating installations or refrigerating circuits can in this way be reduced or avoided.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail on the basis of an exemplary embodiment, but is not restricted to the exemplary embodiment. Further exemplary embodiments are provided by combining the features of one or more of the claims with one another and/or with one or more features of the exemplary embodiment.

In the figures:

FIG. 1 shows a valve controller according to the invention with its components in a schematic representation, and

FIG. 2 shows a schematic representation of the relative sizes of a cylinder and a balance of a valve controller according to the invention.

DETAILED DESCRIPTION

FIG. 1 shows a schematic representation of the various components of a valve controller 1 according to the invention for filling a refrigerating circuit with refrigerant. The valve controller 1 comprises a valve 2, a temperature sensor 3, a pressure sensor 4, a controller 5, a flow sensor 11 and also a balance 12. Multiple components of the valve controller 1 may also be formed together as one unit. In this exemplary embodiment, the valve 2 is a solenoid valve. The controller 5 is formed on a portable handheld device 6, which also comprises a memory 7, an input unit 8 and an output unit 9. The controller is set up to calculate a parameter from the measurement data of the temperature sensor 3 and the pressure sensor 4. The controller 5 activates the valve 2 until the calculated parameter has reached a target value. The memory 7 keeps thermodynamic data on a number of refrigerants, which data are included in the calculation performed by the controller 5. The input unit 8 can be used to choose between different refrigerants. The input unit 8 makes it possible to select target parameters and filling amounts and to establish other data describing the refrigerating circuit, the refrigerant and the filling operation. The respective components of the valve controller 1 are wirelessly connected to one another by way of antennas 10. The data transmission takes place on a number of radio channels simultaneously and at time intervals of less than 10 seconds. The flow sensor 11 and the balance 12 are set up to determine the amount of refrigerant delivered into the refrigerating circuit. This involves the measurement data of the flow sensor 11 and of the balance 12 being processed by the controller 5. Formed on the balance 12 is a weighing platform 13, which serves as a standing surface for a cylinder 14. The cylinder 14 contains the refrigerant to be introduced. The refrigerant can be delivered into the refrigerating circuit by way of a connection 15. The cylinder stands with its standing area 19 on the weighing platform 13 of the balance 12. The controller 5 is also set up to control the filling operation in dependence on the amount of refrigerant delivered and can perform the filling operation iteratively. The controller 5 is also capable of detecting inadmissible states, for example filling with an excessive amount of refrigerant or the occurrence of leakages. The controller 5 is set up to inform the user when an inadmissible state is detected and, in this case, to interrupt the filling operation.

FIG. 2 shows in a schematic representation a plan view of a cylinder 14, which has a round cross-sectional area and also a connection 15. The cylinder 14 stands on a square weighing platform 13, which is indicated by dashed lines. It can be seen in particular that a largest dimension 16 of the weighing platform 13, specifically a diagonal 17 of the weighing platform 13, corresponds to a largest dimension 18 of the standing area 19 of the cylinder 14, specifically a diameter 20 of the cylinder 14.

List of Designations 1 Valve controller 2 Valve 3 Temperature sensor 4 Pressure sensor 5 Controller 6 Handheld device 7 Memory 8 Input unit 9 Output unit 10 Antenna 11 Flow sensor 12 Balance 13 Weighing platform 14 Cylinder 15 Connection 16 Largest dimension 17 Diagonal 18 Largest dimension 19 Standing area 20 Diameter 

1. A valve controller (1) for filling a refrigerating circuit with refrigerant, the valve controller comprising: a valve (2), a temperature sensor (3), a pressure sensor (4), a controller (5) configured to calculate a parameter from at least one of measurement data of the temperature sensor (3) or the pressure sensor (4), and the controller (5) is further configured to activate the valve (2) until the calculated parameter has reached a target value.
 2. The valve controller (1) as claimed in claim 1, further comprising a memory (7) that stores thermodynamic data on a refrigerant, the controller being configured to includes said data in the calculation performed by the controller (5) and to choose between different refrigerants.
 3. The valve controller (1) as claimed in claim 1, wherein at least one of the temperature sensor (3) or the pressure sensor (4) is wirelessly connected to the controller (5), and data transmission take place at least one of on a number of radio channels simultaneously or at time intervals of less than ten seconds.
 4. The valve controller (1) as claimed in claim 1, further comprising at least one of a flow sensor (11) or a balance (12) arranged to determine an amount of refrigerant delivered into the refrigerating circuit, the controller being configured to receive and process measurement data from the at least one of the flow sensor (11) or the balance (12).
 5. The valve controller (1) as claimed in claim 4, wherein the balance (12) is provided, and a weighing platform (13) is formed on the balance (12) as a standing surface for a cylinder (14).
 6. The valve controller (1) as claimed in claim 5, wherein a largest dimension (16) of the weighing platform (13) corresponds to a largest dimension (18) of the standing area (19) of a cylinder (14).
 7. The valve controller (1) as claimed in claim 6, wherein the largest diameter of the weighing platform is a diagonal (17), and a largest diameter of the standing area of the cylinder is a diameter (20) of the cylinder (14).
 8. The valve controller (1) as claimed in claim 1, further comprising an input unit (8) configured for a user to establish at least one of target parameters, filling amounts or other data describing at least one of the refrigerating circuit, the refrigerant, or the filling operation.
 9. The valve controller (1) as claimed in claim 1, wherein the controller (5) is configured to control the filling operation in dependence on an amount of refrigerant delivered.
 10. The valve controller (1) as claimed in claim 9, wherein the controller (5) is configured to iteratively control the filling operation.
 11. The valve controller (1) as claimed in claim 1, wherein the controller (5) is configured to detect an inadmissible state, including at least one of filling with an excessive amount of refrigerant or an occurrence of leakages.
 12. The valve controller (1) as claimed in claim 11, wherein the controller (5) is configured to at least one of inform a user or interrupt a filling operation when the inadmissible state is detected. 